This invention relates to a dosing device for flowable substances, in particular liquids to be sprayed, having a storage vessel for the substance to be dosed and feed means which transports the substance to the discharge opening of the dosing device.
Such dosing devices are known in the form of pump-spray systems which allow liquids, pharmaceutical solutions for example, to be sprayed The known systems first have to be primed by filling the dosing pump, the user being unable to check from which point in time the dosing pump is completely filled and therefore from which point in time the full amount of solution assigned to a pumping movement is sprayed. Therefore, with known pump-spray systems it is not possible to achieve the dosing accuracy of five per cent typically required by registration authorities for medicaments with the dosing pumps available on the market.
Furthermore, the previously known pump-spray systems do not allow a dry substance to be dissolved or suspended in a suitable solvent just before application to the patient and, after the substance has been dissolved or suspended, to be applied precisely and under sterile conditions from a gas-free, e.g. airless, reservoir.